Furnace for domestic heating plants for solid fuel



May 29, 1928. I

w. SCHMIDT FURNACE FOR DOMESTIC HEATING PLANTS FORSOLID FUEL Z 0 9 0 a 6 4 z "m a 2. a W M e z w 4. w a

/4 w l v 9, 2 WW: 2 M 4 Z. Q m m d ll Q r. i F. d F m, .4 o f 3 K4 4 aw m H flu m/ 9 Fig. 1 shows the fire- Patented May 29, 1928.

WILEELM SCHMIDT,

GERMANY.

1,671,549 UNITED STATES, PATENT o-rFicE.

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FURNACE FOR DOMESTLG HEATlI NG PLANTS FOR SQLIl) EU Application filed January 29, 1925, Serial No. 5,588, and in Germany March 29, 1924.

For domestic heating plants only kitchen ranges with natural draught have hitherto been used. Artificial draught has not been used as, on one hand, the expenses for the necessary mechanical plant were too high and as, on the other hand, the attendance of such plants requires skilled workmen. A further reason which prevented the use of artificial draught for dwelling houses is that it is not easy to adapt large-sized heating plants with artificial draught to .the domestic uses.

This invention has for its object to improve domes'tic heating plants so that they may be worked with artificial draught. The invention relates to a device which permits of using, either and which can be added without great cost to any existing stove or kitchen range or ,to any stove or-kitchen range when the same are being manufactured. This device produces the energy required for the artificial draught and ensures by means of this energy the production of a combustible gas mixture (air gas and water gas) the combustion of which takes place in such a manner that the surfaces for heating or cooking purposes are waste gases contain only a minimum of 'com-. bustible constituents. The arrangement according to the invention permits of changing by a simple manipulation from artificial draught to natural ,suction draught and it effects in this case a l reduction ofthegenerally. too large grate surface. I

The arrangement according to the invention is shown, by way of'example, on the accompanying drawing, in which ot and accessories to be inserted into .the 'tchen'range in a vertical section on line I-I of Figs. 2 and 3. Fi 2 is .a vertical section on line II--II of Figs. 1, 3 and 4.

Fig. 3 is a"hor1zontal section on line 111' HIofFigs. 1,2and4.

Fig. 4 is 'an-elevation seen in the directlon ofthearrowAinFig.3. Fig. 5 shows the fire-pot shown 1n Figs. 1

a. vertical section on line V-V of Fig. 6. Y I Fig. 6 is aplan view of 5, the'top 'pleteof the kitchenrange being removed.

artificial or natural draught chamber the mixing and regulating heated rapidly and effectively and that the ply pipe to 4 inserted into" the kitchen range and in packing Fig. 7 shows in front elevation the mixingand regulating-nozzle with the tube f0 distributing the steam and air.

Fig. 8 is a longitudinal section on'line VIII-47TH ofFig. 7..

Fig. 9 shows in longitudinal section the rear end of the pipe coil and the steam'dellvering pipe penetrating into the same. F Fig.10 is a cross section on line X-X of Fig. 11 shows the burner in section on line XIXI of Figs. 12 and 13.

12 is a planview of the burner.

1 view d in the direction of the arrow B in Figs. 11 and 12. 1

Fig. 14% shows elevation, partly in section, the inlet valve for the water to be evaporated.

Referring to Figs. 1 to 6; 1 designates a pipe coil for'producing and superheating steam. This pipe coil 1 is mounted upon the fire-pot 2 in which the fuel is placed on the grate 3. All these elements are mounted on chamber 5 in the grate support kitchen range (Fig. 5) adjacent WhlOll nozzle 6 with the steam distributing ipe (Figs. 7 and 8) and the damper8 or throttling the air forced under the grate, are mounted. A supply pipelO for the water to be trans formed into steam (Figs. 1, 3, 4 and 6) is to the. front end of the pipe coil 1, a valve 9 (Fig.14) being inserted between the supand the pipe coil. The valve "9 regulates In order to prevent the inflow of an excesthe inflow of water to the coil 1.

13 is a'front elevation 'of the burner 4 of the f static pressure exists, and at the other endsive quantity ofi water into the pipe coil 1;

owing to careless o ening of valve 9 a'regulating nozzle 116g bore of which'is sure in the water mam and WhlCh allows only so much water'to pass. through as the heat- Fig. 14 is inserted the regulating nozzle 1-1 has a copper tube 14 is (Figs. 2,

apted to the actual pressurface of the pi e coil 1 can'evaporateeasily at normal working The 3 and 4 The '12 which carries a'filter 13 to pro- Y top end of tube 14 is inserted into the pipe ;coil 1 so that the steam is drawn ofl from coil-lat thehighest point of said coil (Flgs.

9 and The;steam delivering tube 14 terminatesat the lower end in a steam nozzle '15 (Figs. 2 and 4), which opens into the mixin and regulating nozzle 6 (Figs.

7, '8) whic communicateswith the steamai'r distributing pipe 7. The mixing andregulating nozzle is constructed on the principle of.double injecting eflect. Through the inner cone 28 a uniform quantity of air is sucked in when the steam pressure remains uniform, said air mixing with the steam. In order to alter the percentage of air in the mixture when the steam pressure,.

on which depends the intensity of the artificial draught, remains uniform, a second inlet cone 17 is arranged (Fig. 8) which has adjustable inlet holes 16. In this manner it is possible to adapt the proportion of steam to air to the percentage of moisture of the fuel used, the strength of draught re-- maining' the same. The distributing tube 7 for the mixture of steam and air is connected with the mixing and regulating nozzle 6, said tube 7 having narrow slots 18 (Fig. 8) through which the steam and airmixture flows out under the grate 3.

mounte by means of feet 23 (Figs. 1, 2, 4,

5, and 11) upon'the pipe coil l'as shown in Figs..-1, 2, 4, 5 and 6. The auxiliary air necessary for, carrlyl ing out the combustion is admitted throug slots 24 arranged in'the side walls of the kitchen range (Figs. 5

w and "6) a damper being arranged for regulating the air admission.

The operation is as follows When the fuel in the fireot 2 is red he the damper 8, which up to t is moment had Y been open, is closed and consequently the natural draught-throttled. The valve 9 inserted in the water supply pipe 10 is opened so that it regulates theadmlssion of water to the pipe coil 1. According to theadjusting of valve 9 the water enters into the pipe e011 1 either drop by drop-or in a thin Jet and it is instantaneously transformed into steam, said steam being superheated in traversing the pipe coil 1. The superheated steam flows. from the pipe coil 1 through the tube 141 into the steim giifizzle 15 anld, hence into t 1e mixin an re ating nozz e 6inwhichitislnixedwithain mixture of steam and air is distributed through tube 7 inchamber 5 under the gratr 3. When the steam and air mixture flow: through the incandescent layer of fuel z mixture of airgas and water gas is pro duced according to the well known l aws,;t-h1 composition of which mixture depends or the actual proportion between steam and ail and on the reduction temperature due t( the strength of the draught. These highly heatcclcombustible gases transmit, wheI traversing the upper layers of fuel, a por tion of their tangible heat to these layer: of fuel and distill the same. The product: from distillation and the mixture'of wate1 gas and airgas unite to form a highly valuable combustible gas mixture which ascend: from the fire-pot 2, passes throughbetweel the coils of pipe 1 and flows through between the several tubes 21 of which thr burner 19 is composed. The preliminarily heated air flowing out of the burner tube: 21 and which is on to of the ascending gas: and air mixture ignites the latter. Th burnt gases flow to the left. (Fig.6) out through thefiue 30 into the chimney.

If in the intervals between the boiling o1 heating periods the fire has to be reduced valve 9- is closed so that the water admissior is interrupted and the damper 8 is opened in order to reestablish the natural ail draught from'below the grate. I order tc enable .the discharge of the Water which has the highest point of said pipe coil with said injecting nozzle to conduct the super heated steam from the said pipe coil to a distributing pipe below said fire-pot having an air nozzle, said injecting nozzle communicating with said air nozzle to inject steam and induce air into said distributing pipe for'discharge below the fire-pot, a burner consist? ing 'ofa number of tubes having outflow openings'said burner beinglarranged above said pipe coil so, that the gases from combustion ascend-ing from said fire-pot ascend between said burner tubes, means for re ulating' the admission of. outer air into sald burner tubes, said air being preliminarily heated in said burnertubes by the heat from the fire-pot so. that the heated air flowing from said burner tubes on top of said ascending gases from This oombustion ignite the same, and a chimney menses flue at the end of the-kitchen range opposite to said' burner for conducting the waste gases into the chimney.

2. In a kitchen range, comprising in combination with the fire-pot, a pipe coil above said fire-pot, a pipe for supplying water from a water main to said pipe coil, a regulating valvein said pipe, a regulating nozzle in said valve for regulating the admission of water to said pipe coil, an injecting nozzle underneath the grate in said fire-pot,'a pipe open at both ends connecting the highest point of said pipe coil with said injecting nozzle to conduct the super-heated steam from-theipe coil tosaid injecting nozzle, a steam istributing pipe having an air nozzle communicating with said injecting nozzle under the grate of said fire-pot so that the air and steam mixture injected intg said distributing pipe .fromsaid injecting nozzle is forced into the fuel in said firepot from' below, a burner consisting of'a number of tubes having outflow openings said burner being ararnged above the pipe coil softhatthe ases from the combustion ascending from ad fire-pot ascend between said burner-tubes, means .for regulating the admissionof outer air into said burner tubes said air bein preliminarily heated in said burner tubes ythe heat from the 'fireot so that the heated air flowing from the said burn- "v er" tubes on top of said ascending gasesfrom combustion ignite the'same, andfa chimney I flue at the end "of the kitchen range, opposite to said burner for conducting the waste gases. into the-chimney.

3. In a kitchen range draft, comprising in in ecting nozzle to conduct the super-heated steam'from said pipe coil to said injecting nozzle, a distributing. pipe havin nozzle communicating with said lnjecting an air nozzle yvhereby air and steam mixture is distributed below the firepot, a burner consisting of a number of tubes having outflow openings said burner being arranged above said pipe coil so that'the ases from combustion ascending from sai fire-pot ascend between said burner tubes, means for regulating the admission of outer air into said burner tubes said air being reliminarily heated in said burner tubes by the heat from the fire-pot so that the heated air flowing from said vburner tubes on top of said ascending gases from combustion ignite in the same, and a chimney flue at the end of the kitchen range opposite to the said burner for conducting the waste gases into the chimney. 3

In testimony whereof I aflix'my signature.

WILHELM SCHMIDT. 

